Last week Mark shared Part 1 of this series – read it here first.
Next step is to recreate Keiller’s excavation grid using the step-by-step measurements and drawings in his 1934-5 Plotting Book. I could have taken a digital approach from the outset, but to limber up, and better understand how the grid of planned excavation cuttings slowly unfolded on the 10th of April 1934, I began by hand-plotting his measurements, to scale, on a sheet of drawing film.
It all began for Keiller with the setting up of a point on the central axis of the Avenue line. The focus of the 1934 excavation was Mr. Peake-Garland’s main Waden Hill field; a strip running north-south alongside the road linking Avebury to West Kennett. Keiller started by establishing a centre line along the main axis of the Avenue at the southernmost end of the field, where 11 surviving stones could be seen (9 fallen and 2 still standing as a pair). He used a tape to measure the midpoint between the southernmost duo of fallen stones (37A and 37B using Smith’s numbering scheme) and did the same between the surviving upright stones 33A and 33B. He then joined the dots to create a notional line running down the centre of the Avenue and established a reference point (labelled A) on this line.
Using a theodolite the next step was to set out two points perpendicular to A and at a distance of 40’ (12.19m) to the approximate east (C) and west (B) respectively. These points marked the east and westernmost extensions of the grid needed to encompass the width of the Avenue line. So far so good. Using this line of 3 points as a reference, Keiller then set out an 80’ (24.38m) wide corridor running to the northwest towards Avebury. This corridor was subdivided along its length into a series of numbered 100’ x 80’ (30.48 x 24.38m) blocks which were in turn subdivided into parallel lines of 25’ by 20’ (7.62 x 6.09m) cuttings designed to capture the locations of Avenue stones (more on the rather idiosyncratic coding of these blocks and sub-divisions in the next post).
What Keiller and his team had achieved with a theodolite and 100’ survey chains, I was mirroring using a sharp pencil, drawing film and graph paper; working page by page through the plotting book…